Recently there has been considerable interest in glasses doped with CdS.sub.x Se.sub.1-x semiconductor microcrystallites. This has been due to interest in the fundamental physics of low dimensional systems, as well as the technologically important areas associated with optical switching as referred to in K. M. Leung, Phys. Rev. A 33, 2461 (1986) and A. I. Ekimovet al. Solid State Comm. 69, 565 (1989). In the case of commercially available colloidally colored filter glasses the crystallite size is of the order of 5-10 nm, making the crystallite larger than the bulk exciton radius, and thus out of the quantum dot regime. These materials have been the subject of several investigations using four wave mixing, interferometric methods and luminescence detection, as mentioned in R. K. Jain et al., J. Opt. Soc. Am. 73,646 (1983) and M. Tomita et al., J. Opt. Soc. Am B 6,165 (1989). From these measurements .chi..sup.(3) (.omega.,.omega.-, .omega.) values have been measured which range from 10.sup.-11 to 10.sup.-7 esu. In addition, a large spread in response times, ranging from 72 .mu.sec to 10 psec, has been observed along with an intensity dependence. Other effects which are indirectly associated with these observations are thermally reversible photodarkening, non-quadratic dependence of phase conjugate reflectivity on pump intensity, Franz-Keldysh oscillations, and luminescence.
It is an object of this invention to provide second harmonic generation (SHG) in glasses doped with semiconductor microcrystallites.
It is another object of the invention to provide a method of preparing a semiconductor doped glass material so as to exhibit SHG.
It is a further object of the invention to provide SHG in a silica-based glass that contains, by example, CdS.sub.x Se.sub.1-x or CuCl microcrystallites.
It is one further object of the invention to provide optical waveguide structures, optical switching devices, and holographic memory devices that are fabricated with a silica-based glass that contains semiconductor microcrystallites.
It is another object of the invention to provide a lasant material that simultaneously lases and frequency doubles the laser radiation.
It is one further object of the invention to provide a semiconductor laser diode that includes a frequency doubler comprised of a semiconductor microcrystallite doped glass.